Method of making screw-taps.



PATENTED JULY 31, 1906. HNSON.

ING SCREW TAPS.

LED IEB.8.1905.

F. E. J0

METHOD OF MAK APPLICATION or bar to be rol ed to shape.

elevation of the rolls for rolling such bar to cut the FRANK E. JoHNsoN,OF GREENSBURG, PENNSYLVANIA.

METHOD oF- MAKING SCREW-TAPS.

Specification of Letters Patent.

Patented July 31, 1906.

Application am February 8.1905. Serial No. 244,704.

To all whom it may concern:

Be it known that I, FRANK E. J on soN, a resident of Greens'burg, in thecounty 0 Westmoreland and State of Pennsylvania, have invented a new anduseful Improvement inMethods of Making Screw-Taps; and

clear, and exact description thereof. My invention relates to makingscrew-taps. Heretofore inthemanufacture of screwtaps it sections for thetaps from a round bar, then turn the same to formthe shank and bodyflutes in the bodyof each section by milling, after which the body isscrew-threaded and pointed.

The 'objectof my invention is to rovide a cheap, simple, and efiectivemetho of forming'screw-taps which will do away with the laborious anexpensive milling for the flutes, so that a great saving in the weightof the steel to be rolled forsuch screw-taps is accomplished, and thecost'of the manufacture of the same is t ereby greatly cheapened.

My inventio consists, generally stated, in

the novel method hereinafter more specifically set forth and described,and particularly pointed out in the claims..-

To enable others skilled in the art to which my-invention appertains topractice my improved method of makin screw-taps, I will describe thesame more in. l referring to the accompanying drawings, in which-'Figure 1 is a erspective view shape. Figs. 3, 4., 5, andfi? arecross-sections of such bar as'it is rolled to different shapes for thefinished bar. Fi .7 is a side elevation of the finished bar. Fig. 8 is aside view of the tap, as severed from the finished bar and with theshank formed thereon."

.Fiifilis a viewof the'finished tap.

ke symbols of reference herein indicate like parts of each of thefigures of the drawmgs.

The billet orbal' a to be rolled is referably flat or square incross-section an is, of the. roper size, so that when it is heated itcan e assed through the reducing-pass -1 of the ro s Aj as shown bydotted lines in Fig. 2, and after such bar a has been so reduced toshape shown'in Fig. 3 by passing through the pass 1 it can be passedthroughthreducing- I do hereby declare the following to be a full,

the method of has been general and customary 'to to the size required,then form the .a deeper groove of the billetv Fig. 2 is a side pass 2 toassume the shape shown in Fig. 4. The bar a is now ready to be formedinto its f finished shape, and this can be accomplished by passing thesame through the finishingpass 3, which pass will cause said bar toassume the'shape shown in Fig. 5 and form the flutes a therein. Thefluted bar a, being now in its finished shape, it is now ready to :becut into blanks or sections 7) for the different-sized tape, as shownin..Fig.. 7, and this can'be done 111 any suitable manner or by anysuitable means After the sections b have been cut orsevered from the bara a shank c is turned on each of said sections by machine- I Work, and,if desired, the fiat or square end 0 at end of the shank may be producedin the "usual manner for a hand-tap, as shown in Figs. 8 and 9. The.formin of said shank leaves the body portion (1 at t e opposite end ofthe section. The'body ortion d can then be finished for the particu arstyle of tap de-- sired, and, if desired, ointed, as at g, Fig. 9. Itwill be understoo that the se uence of operationsinforming' the taaftert eblanks have been cut from the r0 led'bar. may be varied fromthat just described.

Itfl willbe evident that for a smaller size the bar a can be passedthrough another tap finishing-pass 4 in the rolls A, so as to bring thebar downto the shape andlsize shown in Fig. 6 and that other reducingand finishing asses can be formed in the'same set of rolls or formingbars for 'difierent sha es and sizes of taps, while it will also be evient that of the bar in order to enable the end to be q k y, tions,modifications, and changes in carrying out my improved" method of makingscrewtaps may be resorted to. without. departing can be formed in therolling v from the spirit of-the invention or sacrificing an} of itsadvantages.

will thus. be seen that in the use of my improved method of makingscrew-taps a fiat sided or square billet or bar of tool-steel can berolled out to approximate shape and size for the making of pipe-taps,taper taps, lugtaps, bottoming-taps, or any other style of taps i greatadvantage in many ways over the ordinary way of making ta s from a roundbar. In the rolling of sue a bar to the size and shape for taps there isa saving of about fifty per cent. in the weight 'of t e steel rolled bythis desired, and practical experience has proved the method to have aIIO . as to the other.

' is used an enormous savin more bar. t Wil also be seen that a right orleft hand tap can be made from the same barand the same cutting edge canbe given'to the one The steel is rolled out in long bars, so that anumber of sections or blanks for forming taps can be cut therefrom,

and the shape of such bar When rolled is suitable for whatever size tapsare to be made.

It will also be evident that a round of othershaped bar could be rolledto the desired shape, although such operation would robably require afew more passes in the rol s than. is required for the other'shaped barsto bring it down to the desired shape for forming the fluted bar. Agreat many other advantages Will be a parent to tap-makers in the use'ofthis method over the ordinary milling of a round bar generally used forthis class of yvo'rka's, forexample, -if high-s eed steel operation ismade. Anot the rolling of the-lands and obtain a closer grainof steel inthe lands by or advantage in rolling, as the lands and flutes are formedat.

one and the-same time, and there is no interto-secure by Letters over te milling flutes is that you ruption of the grain of the, metal incidentto the milling or cutting out of theflutes. In the ordinary mannerofmakin ta s it is necessary to cut a keyway in the s an or form a squarecut on the same for curing it in the holder.

.What .I claim as, m invention, and desire l atent, is v 1. The methodof making screw-ta s, consisting in rolling a'bar into a grooved s1apeto form lands and flutes for the bodies of the taps, cuttingsections from said bar of the desired length, cutting away the landson-one portion of each section to form a shank, and forming thescrew-cutting edges onthe remainder of each section, substantially asdescribed. i

2. The method of forming screw-ta s, consistin in rolling a bar into arooved s ape to form ands and flutes for t taps, cutting sections fromsaid barof the-desired length, reducing the lands on one end'of eachsection to form a shank, and forming the-screW-cutting edges on-theremainder of each section, substantially as described.- a

In testimony whereof I, the said FRANK 'E'. JoHNsoN, have hereunto setmy hand.

FRANK E. JOHNSON.

I Witnesses:

W. C. Loon, J. B. HUNTER.

the purpose of se-' e bodies of the.

